This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are using a visual stimulus paradigm that produces well-characterized localized neural inhibition in primary visual cortex to test whether, on a fine spatial scale, the positive BOLD response is more closely related to the neural output or the local neural inhibition. In the past year we have published one paper demonstrating that the V1 BOLD response correlates better with the magnitude of the local neural inhibition than with the local neural output;a second manuscript is in preparation.